<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        div {
            width: 200px;
            height: 200px;
            border: 2px solid black;
            /* text-align: center; */
            /* overflow: hidden; */
            position: relative;
        }
        
        div::after {
            position: absolute;
            content: "";
            /* display: block; */
            width: 100%;
            height: 100%;
            transform-origin: left bottom;
            background-color: blue;
            /* transform: rotate(180deg); */
        }
        
        div:hover::after {
            transform: rotate(0);
        }
    </style>
</head>

<body>
    <div></div>
</body>

</html>